Temperature and roasting time

• For big, sturdy vegetables like whole parsnips, halved sweet potatoes or cauliflower steaks: Start at 400 degrees because they need more time to cook through.
• For medium-sized pieces — stems of broccoli, butternut squash chunks or quartered beets — start at 425 degrees.
• For small and tender vegetables, such as green beans, asparagus or sliced carrots, start at 450 degrees so that they’ll char quickly.
• To roast a mix of vegetables, cut similar densities the same size and softer produce larger.

Vegetables are ready when nicely browned, and a paring knife can slide easily through them.